UNEP/POPS/POPRC.3/12

UNITED
NATIONS / SC
UNEP/POPS/POPRC.3/12
/ United Nations
Environment
Programme / Distr.: General
3 September 2007
Original: English

19

UNEP/POPS/POPRC.3/12

Stockholm Convention on Persistent Organic Pollutants

Persistent Organic Pollutants Review Committee

Third meeting

Geneva, 19–23 November 2007

Item 6 (d) of the provisional agenda[*]

Consideration of draft risk management evaluations: lindane

Draft risk management evaluation: lindane

Note by the Secretariat

1.  At its second meeting, the Persistent Organic Pollutants Review Committee adopted decisionPOPRC2/4 on lindane.[1] By paragraph 3 of the decision, the Committee decided to establish an ad hoc working group to prepare a risk management evaluation that includes an analysis of possible control measures for lindane in accordance with Annex F to the Convention.

2.  The members of the ad hoc working group on lindane and its observers are listed in annex V of document UNEP/POPS/POPRC.2/17.

3.  A standard workplan for the preparation of a draft risk management evaluation was adopted by the Committee at its second meeting.[2]

4.  In accordance with decision POPRC-2/4 and the standard workplan adopted by the Committee, the ad hoc working group on lindane prepared the draft risk management evaluation set forth in the annex to the present note. The draft risk management evaluation has not been formally edited.

Possible action by the Committee

5.  The Committee may wish:

(a)  To adopt, with any amendments which it deems appropriate, the draft risk management evaluation set forth in the annex to the present note;

(b)  To decide, in accordance with paragraph 9 of Article 8 of the Convention, based on the risk profile adopted at its second meeting (UNEP/POPS/POPRC/17/Add.4) and the risk management evaluation, whether the chemical should be recommended for consideration by the Conference of the Parties for listing in Annexes A, B, and/or C.


Annex

LINDANE

DRAFT RISK MANAGEMENT EVALUATION

Draft prepared by the ad hoc working group on

Lindane

under the Persistent Organic Pollutants Review Committee

of the Stockholm Convention

August 2007


Table of contents

Executive summary 5

1. Introduction 6

1.1 Chemical identity of the proposed substance 6

1.2 Conclusions of the Review Committee 7

1.3 Data sources 7

1.4 Status of the chemical under international conventions 7

1.5 Any national or regional control actions taken 8

2. Summary information relevant to the risk management evaluation 9

2.1 Identification of possible control measures 9

2.2 Efficacy and efficiency of possible control measures in meeting risk reduction goals 10

2.3 Information on alternatives (products and processes) 10

2.4 Summary of information on impacts on society of implementing possible control measures 13

2.5 Other considerations 15

3. Synthesis of information 16

4. Concluding statement 17

References 18

Executive summary

Mexico proposed that Lindane be added to Annex A of the Stockholm Convention on June 29, 2005. The POPs Review Committee evaluated Annex D information at its first meeting and concluded that “the screening criteria have been fulfilled for Lindane”. The Review Committee at its second meeting evaluated the risk profile for Lindane in accordance with Annex E, and concluded that “Lindane is likely, as a result of its long range environmental transport, to lead to significant adverse human health and environmental effects such that global action is warranted”.

International initiatives on Lindane include the Protocol on Persistent Organic Pollutants of the Convention on Long-Range Transboundary Air Pollution; the Rotterdam Convention; and the OSPAR Commission for the Protection of the Marine Environment of the Northeast Atlantic.

Lindane is banned for use in 52 countries, restricted or severely restricted in 33 countries, not registered in 10 countries, and registered in 17 countries. Regional actions on Lindane include: The North American Regional Action Plan on Lindane and Other Hexachlorocyclohexane Isomers between Canada, United States and Mexico under the North American Commission for Environmental Cooperation; the Great Lakes Binational Toxics Strategy between the United States and Canada; the European Water Framework Directive 2000/60/EC; the European Union Regulation 850/2004/EC and the European Council Directive 850/2004/EEC, among others.

Lindane control measures currently implemented in several countries include: Production, use, sale and imports prohibition, registrations and use cancellations, clean-up of contaminated sites, and public health advisories and hazard warnings issuing for pharmaceutical uses.

The assessment of the efficacy and efficiency of control measures is country dependent; however, all countries consider that control measures currently implemented are technically feasible. There are several chemical alternatives for Lindane for seed treatment, livestock, and veterinary uses. Alternatives that are currently in use are considered, in general, technically feasible, efficient, available and accessible by the countries that are already using them. A different scenario exists for pharmaceutical alternatives for Lindane, where alternatives are available, but failures have been reported for scabies and lice treatments producing a big concern in relation to the limited number of available alternative products on the market. Non-chemical alternatives for Lindane agricultural uses have also been reviewed. Some information has been received about the cost of replacing Lindane with alternative pesticides in agricultural applications.

Lindane meets several internationally accepted criteria for persistence, bioaccumulation and toxicity. Therefore, the implementation of control measures is expected to reduce the risks from exposure of humans and the environment to Lindane. Implementation of control measures is expected to have positive impacts on biota due to the ease with which Lindane accumulates in wildlife, especially in Arctic wildlife. There are potential risks identified from dietary exposure, particularly to people in Alaska and the circumpolar Arctic who depend on traditional foods such as fish and marine mammals.

Several countries that have already prohibited or restricted Lindane use, consider the use of existing stockpiles for a set time period as feasible, leaving a limited amount of waste for disposal. Contaminated sites of former Lindane producers, old storages and dumps have to be addressed by several countries.

Canada, the United States, the Czech Republic, the Republic of Zambia and Brazil have mechanisms to monitor and control Lindane. Other countries also have programs to share information concerning Lindane uses, alternatives and regulations.

A thorough review of existing control measures that have already been implemented in several countries, shows that risks from exposure of humans and the environment to Lindane can be reduced significantly. Control measures are also expected to support the goal agreed at the 2002 Johannesburg World Summit on Sustainable Development of ensuring that by the year 2020, chemicals are produced and used in ways that minimize significant adverse impacts on the environment and human health.

Having evaluated the risk profile corresponding to Lindane, and having prepared its risk management evaluation, the POPs Review Committee of the Stockholm Convention concludes that this chemical is likely, as a result of long-range environmental transport, to lead to significant adverse effects on human health and/or the environment, such that global action is warranted.

In accordance with paragraph 9 of Article 8 of the Convention, the Committee recommends the Conference of the Parties to the Stockholm Convention to consider listing and specifying the related control measures of Lindane in Annex A. However, it should be noted there is some information provided by parties and observers pointing to an option for pharmaceutical use exemption.

1.  Introduction

1.1  Chemical identity of the proposed substance

Lindane: gamma-hexachlorocyclohexane

Chemical formula: C6H6Cl6

CAS number: 58-89-9

Molecular weight: 290.83

Physical and chemical properties are shown in Table 1-1.

Table 1-1. Physico-chemical properties of Lindane

Physical state / Crystalline solid
Melting point / 112.5 °C
Boiling point at 760 mmHg / 323.4 °C
Vapor pressure at 20°C / 4.2x10-5 mmHg
Henry’s Law constant at 25°C / 3.5x10-6 atm m3/mol

ATSDR, 2005

Lindane is the common name for the gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane (HCH). Technical HCH is an isomeric mixture that contains mainly five forms differing only by the chlorine atoms orientation (axial or equatorial positions) around the cyclohexane ring (Figure 1-1). The five principal isomers are present in the mixture in the following proportions: alpha-hexachlorocyclohexane (53%–70%) in two enantiomeric forms ((+)alpha-HCH and (-)alpha-HCH), beta-hexachlorocyclohexane (3%–14%), gamma-hexachlorocyclohexane (11%–18%), delta-hexachlorocyclohexane (6%–10%) and epsilon-hexachlorocyclohexane (3%–5%). The gamma isomer is the only isomer showing strong insecticidal properties.

Figure 1-1. Structure of alpha, beta, gamma, delta and epsilon HCH isomers

Modified from Buser et al, 1995.

The term “benzene hexachloride (BHC)” is also commonly used for HCH, but according to IUPAC rules this designation is incorrect. Nevertheless the term is used and therefore, gamma-BHC also designates Lindane. In the present risk profile document, Lindane refers to at least 99% pure gamma-HCH and the BHC term is not used.

1.2  Conclusions of the Review Committee

Mexico proposed that Lindane be added to Annex A of the Stockholm Convention on June 29, 2005. The Persistent Organic Pollutants (POPs) Review Committee at its first meeting evaluated Annex D information and concluded that “the screening criteria have been fulfilled for Lindane” [3], and decided to establish an ad hoc working group to prepare a risk profile.

The POPs Review Committee at its second meeting evaluated the risk profile for Lindane[4] in accordance with Annex E, and concluded that “Lindane is likely, as a result of its long range environmental transport, to lead to significant adverse human health and environmental effects such that global action is warranted”[5].

1.3  Data sources

The following Parties and observers have answered the request for information specified in Annex F of the Convention: Brazil, Canada, Czech Republic, Germany, Japan, Mauritius, Mexico, Monaco, Republic of Zambia, Sweden, Switzerland, Thailand, United States of America, CropLife International and the International POPs Elimination Network. A more elaborated summary of the submissions is provided as separate POPRC/INF document.

1.4  Status of the chemical under international conventions

Lindane is listed as a “substance scheduled for restrictions on use” in Annex II of the 1998 Protocol on Persistent Organic Pollutants of the Convention on Long-Range Transboundary Air Pollution. This means that products in which at least 99% of the HCH isomer is in the gamma form (i.e. Lindane) are restricted to the following uses: 1. Seed treatment. 2. Soil applications directly followed by incorporation into the topsoil surface layer. 3. Professional remedial and industrial treatment of lumber, timber and logs. 4. Public health and veterinary topical insecticide. 5. Non-aerial application to tree seedlings, small-scale lawn use, and indoor and outdoor use for nursery stock and ornamentals. 6. Indoor industrial and residential applications. All restricted uses of Lindane shall be reassessed under the Protocol no later than two years after the date of entry into force. The Protocol entered into force on October 23th, 2003. There are currently 28 Parties to this Protocol. [6]

Lindane, as well as the mixture of HCH isomers, is listed in Annex III of the Rotterdam Convention on the Prior Informed Consent Procedure as “chemicals subject to the prior informed consent procedure”. The Rotterdam Convention entered into force 24 February 2004. There are currently 116 Parties to this Convention. [7]

Hexachlorocyclohexane isomers, including Lindane, are included in the List of Chemicals for Priority Action (Updated 2005) under the OSPAR Commission for the Protection of the Marine Environment of the Northeast Atlantic. Under this initiative, the Hazardous Substance Strategy sets the objective of preventing pollution of the maritime area by continuously reducing discharges, emissions and losses of hazardous substances, with the ultimate aim of achieving concentrations in the marine environment near background values for naturally occurring substances and close to zero for man-made synthetic substances. The OSPAR Convention entered into force on 25 March 1998. [8]

HCH (including Lindane) is listed as a Level II substance in the Great Lakes Binational Toxics Strategy between the United States and Canada, which means that one of the two countries has grounds to indicate its persistence in the environment, potential for bioaccumulation and toxicity. [9]

1.5  Any national or regional control actions taken

Lindane is banned for use in 52 countries, restricted or severely restricted in 33 countries, not registered in 10 countries, and registered in 17 countries (CEC, 2006).

The three Parties (Mexico, Canada and the United States) of the North American Commission for Environmental Cooperation (CEC)[10] have recently signed a North American Regional Action Plan (NARAP) on Lindane and Other Hexachlorocyclohexane Isomers, under the Sound Management of Chemicals project. The goal of the NARAP is to reduce the risks associated with exposure of humans and the environment to these substances.

Lindane is also listed under the European Water Framework Directive 200/60/EC. This Directive is a piece of water legislation from the European Community. It requires all inland and coastal water bodies to reach at least “good ecological status” and “good chemical status” by 2015. Lindane is one of the listed priority hazardous substances for which quality standards and emission controls will be set at EU level to end all emissions within 20 years. [11]

Lindane is listed under the European Union Regulation 850/2004/EC, that specifies Member States may allow until September 2006 professional remedial and industrial treatment of lumber, timber and logs, as well as indoor industrial and residential applications; and until December 31, 2007 the use of technical HCH as an intermediate in chemical manufacturing and the restriction of products containing at least 99% of the HCH gamma isomer for use as public health and veterinary topical insecticide (Annex F information provided by Germany, 2007).

HCH is listed in Annexes IB (banned substances) and Annex IV (waste regulation) of European Council Directive 850/2004/EEC. Regulation 850/2004/EC was lately amended by regulation 1195/2006/EC in order to include thresholds for POPs containing waste. Article 7 applies to waste containing >50 mg/kg of the sum of alpha, beta and gamma HCH (Annex F information provided by Germany, 2007).

2.  Summary information relevant to the risk management evaluation

2.1  Identification of possible control measures

Lindane control measures currently implemented in several countries include: Production, use, sale and imports prohibition, use restrictions, registrations and use cancellations, clean-up of contaminated sites and public health advisories and hazard warnings issued for pharmaceutical uses.